The safety aspect and reliability of detonating of explosives is paramount as the consequences associated unsafe and unreliable detonation can be castrophic. As such there are requirements for the military, other related defence agencies and other users of explosives to safely detonate explosives. Safely in this context means: safely separated in distance; safely separated in time and security of initiation. Explosives can be initiated by electrical circuit cable or other non-electrical ‘cable’, however in cases of electrical initiation, long cable lengths allow greater susceptibly to initiation of the charge via electro-magnetic induction onto the cable (radio signals or lightning strikes).
Security of initiation requires that the explosive must not be initiated falsely, either because of erroneously decoded signals or deliberately spoofed signals. Also to ensure the extremely high level security required, the equipment must be protected against the possibility of the failure of microprocessors and the program code. The firing circuits must also be designed and analysed to a very high standard to ensure that component failure will not result in the firing voltage being incorrectly applied to the explosive circuit.
The remote initiation equipment needs to be as small in volume and as light weight as possible. The radio transmission system needs to operate over a good distance. The equipment needs to be very robust, being carried in an environment that includes; temperatures from −4° C. to +60° C., water depths of 20 metres and in aircraft flying to 30,000 ft.
Current remote initiator (RI) equipment are generally bulky and heavy with weights around 1.5 kg and volumes around 1500 cubic cm. This weight and volume is driven by the need to increase power endurance which leads to existing cumbersome battery solutions. Further the frequency bands may not be well chosen to achieve the required distances. This can also lead to increased power demand through the selected transmitter power level.
RI's having a single microprocessor can be suspect, as either a simple failure of the electronic machine or an untested software path could result in the triggering of the firing circuit. The safest assumption to make about a microprocessor and its program is that it could arbitrarily decide to initiate a firing event. To guard against such an event, a secondary processor with its own independent control of the firing circuit can be incorporated.
None of the existing remote initiators provide simplicity of use. A considerable amount of training and experience is required in any but the most simple of deployments. Also none of the existing RI's would appear to be applicable or designed for explosive method of entry and/or for initiating breaching charges over a short range requiring no physical link between the breacher and the demolition charge.